Ingestion of medium chain fatty acids by lactating dairy cows increases concentrations of plasma ghrelin

The purpose of this study was to elucidate the effects of medium-chain fatty acids (MCFAs) on plasma ghrelin concentration in lactating dairy cows. Five early-lactating Holstein cows were randomly assigned to 2 dietary treatments in a crossover design with 2-wk periods. Treatments consisted of diets supplemented or not (control) with calcium salts of MCFAs (MCFA-Ca; 1.5% dry matter). Plasma hormone and metabolite concentrations in blood samples taken from the jugular vein were measured on the morning of feeding on day 14 of each period. Dry matter intake, milk protein, and lactose content of cows fed the MCFA-Ca diet were decreased compared with controls, but with no change in milk yield. Plasma ghrelin concentrations were higher in cows fed the MCFA-Ca diet; however, no significant effect was found on glucagon-like peptide-1 concentrations in plasma. Plasma insulin concentrations decreased, but plasma glucagon concentrations remained unchanged in cows fed the MCFA-Ca diet. The concentrations of nonesterified FAs, total cholesterol, and β-hydroxybutyrate in plasma increased in these cows. In conclusion, dietary MCFAs increase the plasma ghrelin concentrations in lactating dairy cows.     

Resistant starch for weaning pigs — Effect on concentration of short chain fatty acids in digesta and intestinal morphology

We investigated the effect of potato starch, a source of resistant starch (RS), in diets for newly weaned pigs on production of short chain fatty acids (SCFA) and intestinal morphology. At weaning, at 4 weeks of age, 24 pigs were divided into 3 groups and fed diets containing 0 (C), 80 (P80) or 160 (P160) g raw potato starch per kg feed for 12 days. Pigs fed P160 had the longest villi whereas pigs fed P80 had the deepest crypts. Villous height at the mid-small intestine and average daily gain were positively correlated (r = 0.59, P < 0.01). The daily gain tended to be lower (P = 0.08) for pigs fed P80 than for pigs fed C or P160. The colon weight increased in pigs fed RS which coincided with an increased crypt depth in the colon. The concentration of SCFA increased in the large intestine with increasing amount of RS. The proportion of acetic acid decreased and the proportion of butyric acid increased in pigs fed P80 and P160. The increased SCFA production, especially of butyrate, may explain the colonic growth.     

中短链脂肪酸在无抗饲料中的应用

在现代畜牧业中,为了预防动物疾病和提高生产性能,普遍在饲料中使用抗生素。由于抗生素在畜牧业中的过度使用导致细菌耐药性的产生和抗生素的残留,严重影响到人类和畜禽的健康。因此,迫切地需要制定策略来替代抗生素用于生产食品的动物,特别是畜禽。中短链脂肪酸作为安全高效的添加剂已经畜牧生产中得到广泛的应用,文章以无抗饲料为背景,论述了中短链脂肪酸的研究进展和展望,为无抗饲料开发及使用提供参考。     

Infusion of short chain fatty acids in the ileum improves the carcass traits,meat quality and lipid metabolism of growing pigs

Short chain fatty acids (SCFA) are the main products of indigestible carbohydrates undergoing bacterial fermentation in the hindgut, which are related to some physiological functions. This study was designed to investigate the effects of SCFA infusion by ileum on the carcass traits, meat quality and lipid metabolism of growing pigs. In a 28-day study, 24 growing barrows fitted with a T-cannula in distal ileum were divided into 4 treatments: 1) Control, 2) antibiotics (AB), 3) AB + 300 mL of SCFA1 solution (ABS1), 4) AB + 300 mL of SCFA2 solution (ABS2). The concentrations of acetate, propionate and butyrate in SCFA1 solution were respectively 61.84, 18.62 and 12.55 mmol/L, and in SCFA2 were respectively 40.08, 15.41 and 9.78 mmol/L. The results showed that the SCFA infusion increased the average daily feed intake and average daily gain of pigs (P < 0.05). Meanwhile, the SCFA treatments increased longissimus dorsi area (P < 0.05) and carcass weight (P = 0.058), decreased the drip loss of longissimus dorsi (P = 0.059), and reduced serum concentrations of triglyceride, total cholesterol and urea nitrogen (P < 0.05). Besides, the SCFA administration inhibited the mRNA expressions of fatty acid synthase (FAS) and acetyl-CoA carboxylase in longissimus dorsi (P < 0.05), the mRNA expression of FAS in the liver (P < 0.05), and the mRNA expression of hormone-sensitive lipase in abdominal fat (P < 0.05). Short chain fatty acid infusion also enhanced the mRNA expression of carnitine palmitoyltransferase-1α in the liver (P < 0.05), the mRNA expressions of peroxisome proliferator activated receptor gamma and lipoprotein lipase in abdominal fat (P < 0.05), and the mRNA expressions of free fatty acid receptor 2, glucose-6-phosphatase and phosphoenolpyruvate carboxykinase 1 in the colon (P < 0.05). These results suggested that SCFA administration in the ileum could improve the carcass traits and meat quality of growing pigs, which was possibly due to the fact that SCFA modulated lipid metabolism.     

The production of short chain fatty acid and colonic development in weaning piglets

Weaning process widely affects the small intestinal structure and function in piglets, while the responses of large intestine to weaning stress are still obscure. The purpose of this study was to determine the developmental changes (i.e., short chain fatty acids (SCFAs) concentrations, growth parameters, crypt‐related indices and antioxidant capacity) in colon of piglet during weaning. Forty piglets were weaned at day 21 and euthanized to collect colonic tissues and digesta samples on day 0, 1, 3, 7 and 14 post‐weaning (n = 8). Piglet growth performance was improved (p < .001) on day 7 and 14 post‐weaning. The concentrations of acetate, propionate, butyrate, valerate, isobutyrate, isovalerate and total SCFAs were higher (p < .001) during the late post‐weaning period. The mRNA abundances of SCFAs transporters were greater (p < .001) on day 7 and 14. The absolute and relative weights, absolute length and perimeter of colon were greater (p < .001) on day 7 and 14. Similarly, post‐weaning increases (p < .001) in colonic crypt depth and Ki67 positive cells numbers per crypt were observed during the same period. Colonic crypt fission indices decreased (p < .01), while total crypt numbers increased (p < .001) on day 14 after weaning. Moreover, total SCFAs concentration was significantly associated with colonic growth parameters and Ki67 cells/crypt (p < .001). In addition, catalase content was decreased on day 3, 7, and 14, whereas, the concentrations of total superoxide dismutase (T‐SOD) and manganese‐containing superoxide dismutase (MnSOD) were higher (p < .05) on day 1 and 3 post‐weaning. These results showed that weaning process has a significant effect on colonic growth and development, which might be associated with the change of SCFAs concentrations in colon.     

Effect of short‐chain fatty acids on triacylglycerol accumulation,lipid droplet formation and lipogenic gene expression in goat mammary epithelial cells

Short‐chain fatty acids (SCFAs) are the major energy sources for ruminants and are known to regulate various physiological functions in other species. However, their roles in ruminant milk fat metabolism are still unclear. In this study, goat mammary gland epithelial cells (GMECs) were treated with 3 mmol/L acetate, propionate or butyrate for 24 h to assess their effects on lipogenesis. Data revealed that the content of triacylglycerol (TAG) and lipid droplet formation were significantly stimulated by propionate and butyrate. The expression of FABP3, SCD1, PPARG, SREBP1, DGAT1, AGPAT6 and ADRP were upregulated by propionate and butyrate treatment. In contrast, the messenger RNA (mRNA) expression of FASN and LXRα was not affected by propionate, but reduced by butyrate. Acetate had no obvious effect on the content of TAG and lipid droplets but increased the mRNA expression of SCD1 and FABP3 in GMECs. Additionally, it was observed that propionate significantly increased the relative content of mono‐unsaturated fatty acids (C18:1 and C16:1) at the expense of decreased saturated fatty acids (C16:0 and C18:0). Butyrate and acetate had no significant effect on fatty acid composition. Overall, the results from this work help enhance our understanding of the regulatory role of SCFAs on goat mammary cell lipid metabolism.     

中链脂肪酸在仔猪生产中的研究与应用

中链脂肪酸是一类含有6~12个碳原子的饱和脂肪酸,广泛存在于天然食物中,其对机体具有广泛的有益作用。本文就中链脂肪酸的消化吸收代谢特性、抗菌特性、抗炎抗氧化作用以及在仔猪生产中的应用进行综述,旨在为新型饲料添加剂的开发与利用提供应用和理论依据。     

Different responses in postprandial plasma ghrelin and GH levels induced by concentrate or timothy hay feeding in wethers

Ghrelin and growth hormone (GH) play a key role in regulating energy balance, metabolic hormone secretion and food intake. Ghrelin and GH responses to dietary compositions have not yet been fully clarified, although there may be significant relationships between dietary compositions and ghrelin and GH responses. In the present study, therefore, we assessed whether dietary compositions influence postprandial plasma ghrelin and GH levels in wethers. Four wethers were respectively fed concentrate (C) or timothy hay (R) for 14 days. The levels of total digestive nutrients (TDN) and crude protein (CP) were adjusted to be at the same level. The basal ghrelin in both groups was rapidly and significantly decreased after feeding. Although the decline of ghrelin levels in C was greater and shorter than that in R, no significant difference was observed in the area under the curve (AUC) or in the incremental area. The plasma GH levels were also rapidly and significantly decreased after feeding in both groups and a significant difference was observed between the two groups for AUC of GH. Interestingly, the circadian changes in the plasma ghrelin levels were close to those in the GH levels in C, but this was not the case in R. These data suggest that dietary compositions influence postprandial plasma ghrelin and GH levels, and that these differences may be caused by several factors, including nutrients and ruminal fermentation.     

Effect of fatty acids added to the milk replacer on white scour and excretion of fatty acids in Holstein calves

In order to examine the relationship between white scour and fatty acids, we added fatty acids to the milk replacer. Twenty healthy Holstein calves were divided into 4 groups, five calves per group; a control group with no fortified fatty acid, and 3 groups fed either with oleic, stearic, or palmitic acid, respectively. The calves were fed milk replacer (5% of the calf's body weight) twice a day but the fatty acids (2 wt % of milk replacer) were added only once. The fecal and blood samples were obtained at 0, 12, 24, 36, and 48 h after feeding of the acids. All five calves in the palmitic acid group, and 3 out of 5 calves each in the stealic and the oleic acid groups had whitish feces after feeding fatty acid. The stearic acid group had a significantly elevated stearic acid concentration in the feces during 24–36 h compared to the pre-feeding level. The fecal concentration of palmitic acid increased significantly at 24–36 h in the palmitic acid group. We concluded that the long-chain saturated fatty acids are one of the causes of white scour in calves.     

Effect of dietary supplemental medium chain fatty acids instead of antibiotics on the growth performance,digestibility and blood profiles in growing pigs

Antibiotics have great functions in farm animal. However, the harm of antibiotics can't be ignored. The effects of medium‐chain fatty acids (MCFAs) supplementation to basal diet instead of antibiotics (CSP, Chlortetracycline, sulphonamide dimethazine and procaine penicillin, 1:1:1) on growth performance, nutrient digestibility and blood profile in growing pigs were studied. A total of 140 growing pigs (Landrace × Yorkshire × Duroc) with an average body weight of 27.84 ± 0.42 kg were allotted to four treatments of seven replicates/treatment and five pigs/replicate. The four experimental diets included: CON (basal diet, non‐antibiotic, negative control); CSP (CON + CSP 0.1%, positive control); M1 (CON + MCFA 0.15%) and M2 (CON + MCFA 0.3%). After 5 weeks, the fresh faecal and blood samples were collected from rectum and jugular vein respectively. The average daily gain (ADG) was significantly improved for pigs fed 0.3% MCFAs in relation to basal diet. Meanwhile, CSP supplementation had comparable effect on ADG. The lymphocyte percentage and IgG concentration were higher in blood of pigs‐fed MCFAs in relation to that of CON and CSP treatment while white blood cell and red blood cell were not affected. In relation to basal diet and CSP treatment, the digestibility of dry matter, nitrogen and gross energy (E) were unaffected with MCFAs supplementation. In conclusion, MCFAs improved growth performance on body weight gain and immune profile. Addition 0.3% MCFAs into the diet indicated that its partial positive effect as an alternative to antibiotic.     

排酸处理对湘南黄牛氨基酸以及脂肪酸的影响

[目的]为改善湘南黄牛肉用品质,并在生产中推广应用。[方法]试验选取6头同一品种、月龄接近的湘南黄牛经同一饲喂条件育肥后进行屠宰,测定排酸前后牛肉中氨基酸、脂肪酸含量等指标。[结果]结果表明,排酸牛肉组氨酸、甘氨酸、蛋氨酸、肌氨酸、色氨酸、∑鲜味氨基酸、∑苦味氨基酸含量显著升高(P0.05);丙氨酸、缬氨酸、脯氨酸、苏氨酸、瓜氨酸、∑甜味氨基酸含量显著降低(P0.05)。排酸牛肉十二酸、十四酸、十五酸、顺-11-二十碳烯酸、饱和脂肪酸(SFA)含量显著升高(P0.05);顺-9,12,15-十八碳三烯酸、顺-8,11,14-二十碳三烯酸、顺-5,8,11,14-二十碳四烯酸、二十碳五烯酸、二十二碳六烯酸、多不饱和脂肪酸(PUFA)、PUFA/SFA、n-6 PUFA、n-3 PUFA含量显著降低(P0.05)。[结论]最终得出,通过排酸处理湘南黄牛能够满足人体从肉类摄取氨基酸的需求,同时有效改变脂肪酸含量,提高肉用品质。     

Daily pattern of some fatty acids in the athletic horse

In the sport field, non‐esterified fatty acids (NEFA) are important for the physical performance during the aerobic exercise of short intensity and long duration. In man, rat, goat and in the sedentary horse studies on the chronometabolism showed the presence of a circadian rhythm of the plasmatic concentration of NEFA while data for the athletic horse are lacking. To define a chronogram helpful for a specific planning and the differentiation of the training programmme in the athletic horse, the circadian pattern of some fatty acids (NEFA, palmitic, stearic, oleic, linoleic and linolenic acids) was studied in five Sella Italiana horses. These horses trained following a daily model of activity consisting of walk, trot, gallop and jump of obstacles of different heights. Blood samples were collected from the jugular vein every 4 h, starting at 08:00 hours, for 2 days to assess the concentrations of total NEFA (by spectrophotometry), palmitic, stearic, oleic, linoleic and linolenic acids (by gas chromatography). anova for repeated measures showed a statistical significant effect of the time of the day in NEFA, oleic and linolenic acids. The application of the periodic model showed the periodic pattern of NEFA, oleic, linoleic and linolenic acids. Acrophases were in the afternoon for all parameters. The results obtained showed a different trend of the circadian pattern of the studied parameters in the athletic horse than in the sedentary one because the physical activity and the post‐prandial metabolism acted as zeitgebers.     

龙蒿脂肪酸成分研究

试验对提取的龙蒿Artemisia dracunculus油脂进行甲酯化处理,采用气相色谱技术,首次对龙蒿脂肪酸成分进行了分析,结果表明,龙蒿中含有19种脂肪酸(鉴定17种)。脂肪酸性质评价显示,龙蒿的多不饱和脂肪酸与饱和脂肪酸相对含量比(PUFA/SFA)为3.25,可见龙蒿具有降血脂功能。     

Challenges in enriching milk fat with polyunsaturated fatty acids

Milk fatty acid composition is determined by several factors including diet. The milk fatty acid profile of dairy cows is low in polyunsaturated fatty acids, especially those of the n-3 series. Efforts to change and influence fatty acid profile with longer chain polyunsaturated fatty acids have proven challenging. Several barriers prevent easy transfer of dietary polyunsaturated fatty acids to milk fat including rumen biohydrogenation and fatty acid esterification. The potential for cellular uptake and differences in fatty acid incorporation into milk fat might also have an effect, though this has received less research effort. Given physiological impediments to enriching milk fat with polyunsaturated fatty acids, manipulating the genome of the cow might provide a greater increase than diet alone, but this too may be challenged by the physiology of the cow.     

添加酸马奶源乳酸杆菌对犊牛肠道菌群和短链脂肪酸含量的影响

选取刚出生的健康荷斯坦犊牛20头,随机分为酸马奶组、正常组、腹泻组和抗生素组,每组5头。除正常组外,其他3组在相同哺乳的基础上均口服100 mL致病性E.coli O1菌悬液(2.5×10¹¹ CFU/mL)建立腹泻模型,抗生素组添加环丙沙星0.5 mg/kg,试验期15 d。结果表明：酸马奶组犊牛肠道微生物丰富度与多样性显著高于其他3组(P<0.05)。酸马奶源乳酸杆菌干预后显著提高了肠道内厚壁菌门、普雷沃氏菌科、毛螺菌科未确定菌属和拟普雷沃菌属的相对丰度,降低了拟杆菌门、变形菌门、梭杆菌门、放线菌门的相对丰度;酸马奶组犊牛粪便中乙酸、丙酸和丁酸含量显著高于其他3组(P<0.05)。由此可见,犊牛日粮中添加酸马奶源乳酸杆菌可显著提高肠道微生物多样性,增加肠道中有益菌的丰度,降低有害菌的丰度,并显著提高其粪便中乙酸、丙酸和丁酸的含量。     

Effects of medium‐chain fatty acid‐cyclodextrin complexes on ruminal methane production in vitro

The purpose of the present study was to evaluate effects of medium‐chain fatty acid‐cyclodextrin (CD) complexes on ruminal methane and volatile fatty acid production, and protozoal activity in vitro. Medium‐chain fatty acid‐CDs used in this study were caprylic acid (C8)‐αCD or ‐βCD, capric acid (C10)‐αCD or ‐βCD, and lauric acid (C12)‐αCD or ‐βCD. A 60‐mL of diluted rumen fluid was incubated anaerobically at 38°C for 6 h with the addition of the complex (10–40 mg as fatty acid). Each of the fatty acid‐CDs reduced the number of protozoa, with the order C10 > C12 > C8, and βCD complexes were more effective than αCD complexes. Molar proportions of acetic acid remained unchanged with the addition of fatty acid‐CD, while that of propionic acid increased, being significant for C8‐αCD and βCD, and C10‐αCD and βCD (P < 0.05). Hydrogen production decreased by about 70% of control with the addition of 40 mg of C8 and C10‐CD, on the other hand, it tended to increase with the addition of C12‐CD in both αCD and βCD. Methane production decreased by about 20% with the addition of 40 mg of complexes, except for C10‐βCD, which significantly reduced methane production by about 60%. In conclusion, the addition of C8 or C10‐CD to ruminant diets may be effective in reducing methane production.     

Regulation of intestinal health by branched‐chain amino acids

Besides its primary role in the digestion and absorption of nutrients, the intestine also interacts with a complex external milieu, and is the first defense line against noxious pathogens and antigens. Dysfunction of the intestinal barrier is associated with enhanced intestinal permeability and development of various gastrointestinal diseases. The branched‐chain amino acids (BCAAs) are important nutrients, which are the essential substrates for protein biosynthesis. Recently, emerging evidence showed that BCAAs are involved in maintaining intestinal barrier function. It has been reported that dietary supplementation with BCAAs promotes intestinal development, enhances enterocyte proliferation, increases intestinal absorption of amino acids (AA) and glucose, and improves the immune defenses of piglets. The underlying mechanism of these effects is mediated by regulating expression of genes and proteins associate with various signaling pathways. In addition, BCAAs promote the production of beneficial bacteria in the intestine of mice. Compelling evidence supports the notion that BCAAs play important roles in both nutrition and intestinal health. Therefore, as functional amino acids with various physiological effects, BCAAs hold key roles in promoting intestinal development and health in animals and humans.     

水生生物对高不饱和脂肪酸的营养需求

鱼虾必需脂肪酸是指一些不能由机体自身合成而只能由食物提供,以满足其正常生长发育以及维持细胞组织功能所必需的多不饱和脂肪酸.必需脂肪酸对鱼虾的正常生长以及发育繁殖至关重要.本文就水生生物对n-3高度不饱和脂肪酸(n-3 HUFA)和n-6高度不饱和脂肪酸(n-6 HUFA)系列营养需求作一综述.